From dd34200adc01c5217ef09b55905b5c2312d65535 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Tue, 15 Dec 2009 16:47:24 -0800 Subject: [PATCH] signals: send_signal: use si_fromuser() to detect from_ancestor_ns Change send_signal() to use si_fromuser(). From now SEND_SIG_NOINFO triggers the "from_ancestor_ns" check. This fixes reparent_thread()->group_send_sig_info(pdeath_signal) behaviour, before this patch send_signal() does not detect the cross-namespace case when the child of the dying parent belongs to the sub-namespace. This patch can affect the behaviour of send_sig(), kill_pgrp() and kill_pid() when the caller sends the signal to the sub-namespace with "priv == 0" but surprisingly all callers seem to use them correctly, including disassociate_ctty(on_exit). Except: drivers/staging/comedi/drivers/addi-data/*.c incorrectly use send_sig(priv => 0). But his is minor and should be fixed anyway. Reported-by: Daniel Lezcano Signed-off-by: Oleg Nesterov Cc: Roland McGrath Reviewed-by: Sukadev Bhattiprolu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/signal.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/kernel/signal.c b/kernel/signal.c index a0ba428..b65879d 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -960,9 +960,8 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t, int from_ancestor_ns = 0; #ifdef CONFIG_PID_NS - if (!is_si_special(info) && SI_FROMUSER(info) && - task_pid_nr_ns(current, task_active_pid_ns(t)) <= 0) - from_ancestor_ns = 1; + from_ancestor_ns = si_fromuser(info) && + !task_pid_nr_ns(current, task_active_pid_ns(t)); #endif return __send_signal(sig, info, t, group, from_ancestor_ns); -- 2.7.4